xref: /aosp_15_r20/external/mesa3d/src/panfrost/shared/pan_tiling.c (revision 6104692788411f58d303aa86923a9ff6ecaded22)

/*
 * Copyright (c) 2011-2013 Luc Verhaegen <[email protected]>
 * Copyright (c) 2018 Alyssa Rosenzweig <[email protected]>
 * Copyright (c) 2018 Vasily Khoruzhick <[email protected]>
 * Copyright (c) 2019 Collabora, Ltd.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sub license,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 */

#include "pan_tiling.h"
#include <stdbool.h>
#include "util/bitscan.h"
#include "util/macros.h"

/*
 * This file implements software encode/decode of u-interleaved textures.
 * See docs/drivers/panfrost.rst for details on the format.
 *
 * The tricky bit is ordering along the space-filling curve:
 *
 *    | y3 | (x3 ^ y3) | y2 | (y2 ^ x2) | y1 | (y1 ^ x1) | y0 | (y0 ^ x0) |
 *
 * While interleaving bits is trivial in hardware, it is nontrivial in software.
 * The trick is to divide the pattern up:
 *
 *    | y3 | y3 | y2 | y2 | y1 | y1 | y0 | y0 |
 *  ^ |  0 | x3 |  0 | x2 |  0 | x1 |  0 | x0 |
 *
 * That is, duplicate the bits of the Y and space out the bits of the X. The top
 * line is a function only of Y, so it can be calculated once per row and stored
 * in a register. The bottom line is simply X with the bits spaced out. Spacing
 * out the X is easy enough with a LUT, or by subtracting+ANDing the mask
 * pattern (abusing carry bits).
 *
 */

/*
 * Given the lower 4-bits of the Y coordinate, we would like to
 * duplicate every bit over. So instead of 0b1010, we would like
 * 0b11001100. The idea is that for the bits in the solely Y place, we
 * get a Y place, and the bits in the XOR place *also* get a Y.
 */
/* clang-format off */
const uint32_t bit_duplication[16] = {
   0b00000000,
   0b00000011,
   0b00001100,
   0b00001111,
   0b00110000,
   0b00110011,
   0b00111100,
   0b00111111,
   0b11000000,
   0b11000011,
   0b11001100,
   0b11001111,
   0b11110000,
   0b11110011,
   0b11111100,
   0b11111111,
};
/* clang-format on */

/*
 * Space the bits out of a 4-bit nibble
 */
/* clang-format off */
const unsigned space_4[16] = {
   0b0000000,
   0b0000001,
   0b0000100,
   0b0000101,
   0b0010000,
   0b0010001,
   0b0010100,
   0b0010101,
   0b1000000,
   0b1000001,
   0b1000100,
   0b1000101,
   0b1010000,
   0b1010001,
   0b1010100,
   0b1010101
};
/* clang-format on */

/* The scheme uses 16x16 tiles */

#define TILE_WIDTH      16
#define TILE_HEIGHT     16
#define PIXELS_PER_TILE (TILE_WIDTH * TILE_HEIGHT)

/* We need a 128-bit type for idiomatically tiling bpp128 formats. The type must
 * only support copies and sizeof, so emulating with a packed structure works
 * well enough, but if there's a native 128-bit type we may we well prefer
 * that. */

#ifdef __SIZEOF_INT128__
typedef __uint128_t pan_uint128_t;
#else
typedef struct {
   uint64_t lo;
   uint64_t hi;
} __attribute__((packed)) pan_uint128_t;
#endif

typedef struct {
   uint16_t lo;
   uint8_t hi;
} __attribute__((packed)) pan_uint24_t;

typedef struct {
   uint32_t lo;
   uint16_t hi;
} __attribute__((packed)) pan_uint48_t;

typedef struct {
   uint64_t lo;
   uint32_t hi;
} __attribute__((packed)) pan_uint96_t;

/* Optimized routine to tile an aligned (w & 0xF == 0) texture. Explanation:
 *
 * dest_start precomputes the offset to the beginning of the first horizontal
 * tile we're writing to, knowing that x is 16-aligned. Tiles themselves are
 * stored linearly, so we get the X tile number by shifting and then multiply
 * by the bytes per tile .
 *
 * We iterate across the pixels we're trying to store in source-order. For each
 * row in the destination image, we figure out which row of 16x16 block we're
 * in, by slicing off the lower 4-bits (block_y).
 *
 * dest then precomputes the location of the top-left corner of the block the
 * row starts in. In pixel coordinates (where the origin is the top-left),
 * (block_y, 0) is the top-left corner of the leftmost tile in this row.  While
 * pixels are reordered within a block, the blocks themselves are stored
 * linearly, so multiplying block_y by the pixel stride of the destination
 * image equals the byte offset of that top-left corner of the block this row
 * is in.
 *
 * On the other hand, the source is linear so we compute the locations of the
 * start and end of the row in the source by a simple linear addressing.
 *
 * For indexing within the tile, we need to XOR with the [y3 y3 y2 y2 y1 y1 y0
 * y0] value. Since this is constant across a row, we look it up per-row and
 * store in expanded_y.
 *
 * Finally, we iterate each row in source order. In the outer loop, we iterate
 * each 16 pixel tile. Within each tile, we iterate the 16 pixels (this should
 * be unrolled), calculating the index within the tile and writing.
 */

#define TILED_ACCESS_TYPE(pixel_t, shift)                                      \
   static ALWAYS_INLINE void panfrost_access_tiled_image_##pixel_t(            \
      void *dst, void *src, uint16_t sx, uint16_t sy, uint16_t w, uint16_t h,  \
      uint32_t dst_stride, uint32_t src_stride, bool is_store)                 \
   {                                                                           \
      uint8_t *dest_start =                                                    \
         dst + ((sx >> 4) * PIXELS_PER_TILE * sizeof(pixel_t));                \
      for (int y = sy, src_y = 0; src_y < h; ++y, ++src_y) {                   \
         uint8_t *dest = (uint8_t *)(dest_start + ((y >> 4) * dst_stride));    \
         pixel_t *source = src + (src_y * src_stride);                         \
         pixel_t *source_end = source + w;                                     \
         unsigned expanded_y = bit_duplication[y & 0xF] << shift;              \
         for (; source < source_end; dest += (PIXELS_PER_TILE << shift)) {     \
            for (uint8_t i = 0; i < 16; ++i) {                                 \
               unsigned index = expanded_y ^ (space_4[i] << shift);            \
               if (is_store)                                                   \
                  *((pixel_t *)(dest + index)) = *(source++);                  \
               else                                                            \
                  *(source++) = *((pixel_t *)(dest + index));                  \
            }                                                                  \
         }                                                                     \
      }                                                                        \
   }

TILED_ACCESS_TYPE(uint8_t, 0);
TILED_ACCESS_TYPE(uint16_t, 1);
TILED_ACCESS_TYPE(uint32_t, 2);
TILED_ACCESS_TYPE(uint64_t, 3);
TILED_ACCESS_TYPE(pan_uint128_t, 4);

#define TILED_UNALIGNED_TYPE(pixel_t, is_store, tile_shift)                    \
   {                                                                           \
      const unsigned mask = (1 << tile_shift) - 1;                             \
      for (int y = sy, src_y = 0; src_y < h; ++y, ++src_y) {                   \
         unsigned block_start_s = (y >> tile_shift) * dst_stride;              \
         unsigned source_start = src_y * src_stride;                           \
         unsigned expanded_y = bit_duplication[y & mask];                      \
                                                                               \
         for (int x = sx, src_x = 0; src_x < w; ++x, ++src_x) {                \
            unsigned block_x_s = (x >> tile_shift) * (1 << (tile_shift * 2));  \
            unsigned index = expanded_y ^ space_4[x & mask];                   \
            uint8_t *source = src + source_start + sizeof(pixel_t) * src_x;    \
            uint8_t *dest =                                                    \
               dst + block_start_s + sizeof(pixel_t) * (block_x_s + index);    \
                                                                               \
            pixel_t *outp = (pixel_t *)(is_store ? dest : source);             \
            pixel_t *inp = (pixel_t *)(is_store ? source : dest);              \
            *outp = *inp;                                                      \
         }                                                                     \
      }                                                                        \
   }

#define TILED_UNALIGNED_TYPES(store, shift)                                    \
   {                                                                           \
      if (bpp == 8)                                                            \
         TILED_UNALIGNED_TYPE(uint8_t, store, shift)                           \
      else if (bpp == 16)                                                      \
         TILED_UNALIGNED_TYPE(uint16_t, store, shift)                          \
      else if (bpp == 24)                                                      \
         TILED_UNALIGNED_TYPE(pan_uint24_t, store, shift)                      \
      else if (bpp == 32)                                                      \
         TILED_UNALIGNED_TYPE(uint32_t, store, shift)                          \
      else if (bpp == 48)                                                      \
         TILED_UNALIGNED_TYPE(pan_uint48_t, store, shift)                      \
      else if (bpp == 64)                                                      \
         TILED_UNALIGNED_TYPE(uint64_t, store, shift)                          \
      else if (bpp == 96)                                                      \
         TILED_UNALIGNED_TYPE(pan_uint96_t, store, shift)                      \
      else if (bpp == 128)                                                     \
         TILED_UNALIGNED_TYPE(pan_uint128_t, store, shift)                     \
   }

/*
 * Perform a generic access to a tiled image with a given format. This works
 * even for block-compressed images on entire blocks at a time. sx/sy/w/h are
 * specified in pixels, not blocks, but our internal routines work in blocks,
 * so we divide here. Alignment is assumed.
 */
static void
panfrost_access_tiled_image_generic(void *dst, void *src, unsigned sx,
                                    unsigned sy, unsigned w, unsigned h,
                                    uint32_t dst_stride, uint32_t src_stride,
                                    const struct util_format_description *desc,
                                    bool _is_store)
{
   unsigned bpp = desc->block.bits;

   /* Convert units */
   sx /= desc->block.width;
   sy /= desc->block.height;
   w = DIV_ROUND_UP(w, desc->block.width);
   h = DIV_ROUND_UP(h, desc->block.height);

   if (desc->block.width > 1) {
      if (_is_store)
         TILED_UNALIGNED_TYPES(true, 2)
      else
         TILED_UNALIGNED_TYPES(false, 2)
   } else {
      if (_is_store)
         TILED_UNALIGNED_TYPES(true, 4)
      else
         TILED_UNALIGNED_TYPES(false, 4)
   }
}

#define OFFSET(src, _x, _y)                                                    \
   (void *)((uint8_t *)src + ((_y)-orig_y) * src_stride +                      \
            (((_x)-orig_x) * (bpp / 8)))

static ALWAYS_INLINE void
panfrost_access_tiled_image(void *dst, void *src, unsigned x, unsigned y,
                            unsigned w, unsigned h, uint32_t dst_stride,
                            uint32_t src_stride, enum pipe_format format,
                            bool is_store)
{
   const struct util_format_description *desc = util_format_description(format);
   unsigned bpp = desc->block.bits;

   /* Our optimized routines cannot handle unaligned blocks (without depending
    * on platform-specific behaviour), and there is no good reason to do so. If
    * these assertions fail, there is either a driver bug or a non-portable unit
    * test.
    */
   assert((dst_stride % (bpp / 8)) == 0 && "unaligned destination stride");
   assert((src_stride % (bpp / 8)) == 0 && "unaligned source stride");

   if (desc->block.width > 1 ||
       !util_is_power_of_two_nonzero(desc->block.bits)) {
      panfrost_access_tiled_image_generic(
         dst, (void *)src, x, y, w, h, dst_stride, src_stride, desc, is_store);

      return;
   }

   unsigned first_full_tile_x = DIV_ROUND_UP(x, TILE_WIDTH) * TILE_WIDTH;
   unsigned first_full_tile_y = DIV_ROUND_UP(y, TILE_HEIGHT) * TILE_HEIGHT;
   unsigned last_full_tile_x = ((x + w) / TILE_WIDTH) * TILE_WIDTH;
   unsigned last_full_tile_y = ((y + h) / TILE_HEIGHT) * TILE_HEIGHT;

   /* First, tile the top portion */

   unsigned orig_x = x, orig_y = y;

   if (first_full_tile_y != y) {
      unsigned dist = MIN2(first_full_tile_y - y, h);

      panfrost_access_tiled_image_generic(dst, OFFSET(src, x, y), x, y, w, dist,
                                          dst_stride, src_stride, desc,
                                          is_store);

      if (dist == h)
         return;

      y += dist;
      h -= dist;
   }

   /* Next, the bottom portion */
   if (last_full_tile_y != (y + h)) {
      unsigned dist = (y + h) - last_full_tile_y;

      panfrost_access_tiled_image_generic(
         dst, OFFSET(src, x, last_full_tile_y), x, last_full_tile_y, w, dist,
         dst_stride, src_stride, desc, is_store);

      h -= dist;
   }

   /* The left portion */
   if (first_full_tile_x != x) {
      unsigned dist = MIN2(first_full_tile_x - x, w);

      panfrost_access_tiled_image_generic(dst, OFFSET(src, x, y), x, y, dist, h,
                                          dst_stride, src_stride, desc,
                                          is_store);

      if (dist == w)
         return;

      x += dist;
      w -= dist;
   }

   /* Finally, the right portion */
   if (last_full_tile_x != (x + w)) {
      unsigned dist = (x + w) - last_full_tile_x;

      panfrost_access_tiled_image_generic(
         dst, OFFSET(src, last_full_tile_x, y), last_full_tile_x, y, dist, h,
         dst_stride, src_stride, desc, is_store);

      w -= dist;
   }

   if (bpp == 8)
      panfrost_access_tiled_image_uint8_t(dst, OFFSET(src, x, y), x, y, w, h,
                                          dst_stride, src_stride, is_store);
   else if (bpp == 16)
      panfrost_access_tiled_image_uint16_t(dst, OFFSET(src, x, y), x, y, w, h,
                                           dst_stride, src_stride, is_store);
   else if (bpp == 32)
      panfrost_access_tiled_image_uint32_t(dst, OFFSET(src, x, y), x, y, w, h,
                                           dst_stride, src_stride, is_store);
   else if (bpp == 64)
      panfrost_access_tiled_image_uint64_t(dst, OFFSET(src, x, y), x, y, w, h,
                                           dst_stride, src_stride, is_store);
   else if (bpp == 128)
      panfrost_access_tiled_image_pan_uint128_t(
         dst, OFFSET(src, x, y), x, y, w, h, dst_stride, src_stride, is_store);
}

/**
 * Access a tiled image (load or store). Note: the region of interest (x, y, w,
 * h) is specified in pixels, not blocks. It is expected that these quantities
 * are aligned to the block size.
 */
void
panfrost_store_tiled_image(void *dst, const void *src, unsigned x, unsigned y,
                           unsigned w, unsigned h, uint32_t dst_stride,
                           uint32_t src_stride, enum pipe_format format)
{
   panfrost_access_tiled_image(dst, (void *)src, x, y, w, h, dst_stride,
                               src_stride, format, true);
}

void
panfrost_load_tiled_image(void *dst, const void *src, unsigned x, unsigned y,
                          unsigned w, unsigned h, uint32_t dst_stride,
                          uint32_t src_stride, enum pipe_format format)
{
   panfrost_access_tiled_image((void *)src, dst, x, y, w, h, src_stride,
                               dst_stride, format, false);
}